#include <bits/stdc++.h>

using namespace std;

class Solution
{
public:
    int maxProfit(vector<int> &prices)
    {
        vector<vector<int>> dp(prices.size(), vector<int>(5, 0));
        dp[0][1] = -prices[0];
        dp[0][3] = -prices[0];
        for (int i = 1; i < (int)prices.size(); i++)
        {
            dp[i][1] = max(dp[i - 1][1], dp[i - 1][0] - prices[i]);
            dp[i][2] = max(dp[i - 1][2], dp[i - 1][1] + prices[i]);
            dp[i][3] = max(dp[i - 1][3], dp[i - 1][2] - prices[i]);
            dp[i][4] = max(dp[i - 1][4], dp[i - 1][3] + prices[i]);
        }
        return dp[prices.size() - 1][4];
    }
};

int main()
{
    vector<int> prices{3, 3, 5, 0, 0, 3, 1, 4};
    Solution sol;
    cout << sol.maxProfit(prices) << endl;
    return 0;
}